2008 Pontiac G5 Owner's Manual - Page 133

Entry/Exit Lighting The lamps inside the vehicle will go on when any door is opened. These lamps fade out about 20 seconds after all of the doors have been closed or when the ignition is turned to ON/RUN. These lamps will also go on when pressing the trunk release, unlock symbol, or the horn symbol button on the Remote Keyless Entry System (RKE) Transmitter. After the key is removed from the ignition, the lamps inside the vehicle stay on for about 20 seconds to provide an illuminated exit. When the battery's state of charge is low, the voltage is raised slightly to quickly put the charge back in. When the state of charge is high, the voltage is lowered slightly to prevent overcharging. If the vehicle has a voltmeter gage or voltage display on the Driver Information Center (DIC), you may see the voltage move up or down. This is normal. If there is a problem, an alert will be displayed. The battery can be discharged at idle if the electrical loads are very high. This is true for all vehicles. This is because the generator (alternator) may not be spinning fast enough at idle to produce all the power that is needed for very high electrical loads. A high electrical load occurs when several of the following loads are on: headlamps, high beams, fog lamps, rear window defogger, climate control fan at high speed, heated seats, engine cooling fans, trailer loads, and loads plugged into accessory power outlets. EPM works to prevent excessive discharge of the battery. It does this by balancing the generator's output and the vehicle's electrical needs. It can increase engine idle speed to generate more power, whenever needed. It can temporarily reduce the power demands of some accessories. Normally, these actions occur in steps or levels, without being noticeable. In rare cases at the highest levels of corrective action, this action may be noticeable to the driver. 3-17 Mirror Reading Lamps Your vehicle may have reading lamps on the rearview mirror. Push the button to turn the reading lamps on and off. Electric Power Management This vehicle has Electric Power Management (EPM), an advanced control system. It estimates the battery's temperature and state of charge and then adjusts the voltage for best performance and extended life of the battery.